1. Field of the Invention
The present invention relates to a hub-mounted optical disk that is magnetically mounted on a turntable, a method to fabricate the optical disk, and an injection molding die to manufacture an optical disk substrate, and more particularly, to a hub-mounted optical disk designed to eliminate the need for a separate stack ring while reducing the overall height, a method to fabricate the optical disk, and an injection molding die to manufacture an optical disk substrate.
2. Description of the Related Art
Typically, a slim optical recording/reproducing apparatus employs a technique in which an optical disk is mounted on a turntable fixed to a rotating axis of a spindle motor by a magnetic attraction force that is produced by a magnet. To this end, the apparatus adopts an optical disk to which a hub made of magnetic material is affixed.
Referring to FIG. 1, a conventional hub-mounted optical disk includes a substrate 1 having a hollow 1a and a hub 10 inserted into the hollow 1a. The hub 10 is comprised of an engaging portion 11 which is inserted into the hollow 1a and a flange 13 that covers a portion of an inside surface of the substrate 1. The hub 10 having a seating hole 10a is made from magnetic material.
A slim optical recording and/or reproducing apparatus includes a spindle motor 20 having a rotating axis 25, a turntable 21 fixed to the rotating axis 25, and a magnet 23 mounted on the turntable 21. The rotating axis 25 projects through a space at the center of the turntable 21. Thus, when the optical disk is installed such that the rotating axis 25 fits into the seating hole 10a, the optical disk is mounted on the turntable 21 by magnetic attraction between the flange 13 and the magnet 23.
Here, the flange 13 projects toward one side of the substrate 1, which makes reducing the overall thickness of the optical disk and realizing a compact optical disk drive difficult.